KVM: s390: don't switch to ESCA for ucontrol

sca_add_vpcu is not called for ucontrol guests. We must also not
apply the sca checking for sca_can_add_vcpu as ucontrol guests
do not have to follow the sca limits.

As common code already checks that id < KVM_MAX_VCPUS all other
data structures are safe as well.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d9d71bb..539d385 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1588,7 +1588,7 @@
 	struct sie_page *sie_page;
 	int rc = -EINVAL;
 
-	if (!sca_can_add_vcpu(kvm, id))
+	if (!kvm_is_ucontrol(kvm) && !sca_can_add_vcpu(kvm, id))
 		goto out;
 
 	rc = -ENOMEM;